1. Field of the Invention
The present invention relates to a recording/reproducing device, having a pickup unit having a head mounted thereon, for selecting a desired disk from a magazine which accommodates a plurality of disks therein to read or write data or read and write data between the selected disk and the head.
2. Description of the Related Art
In general, a recording/reproducing device, i.e., a CD-ROM changer is designed to be able to insert/discharge a magazine which accommodates a plurality of recording media therein into/from an insertion port.
In the CD-ROM changer, a disk selected from a plurality of CD-ROMs (disk-like recording media: to be referred to as disks hereinafter) in the inserted magazine is moved into a pickup unit (or in the reverse direction in a discharge state) such that the drive force of a motor is reduced by a gear train to drive a tray loading mechanism.
In this case, the pickup unit is elevated to the stage (level) of the selected disk by a level-positioning mechanism to be stopped at the stage. FIG. 10 is a view for explaining the outline of a conventional level-positioning mechanism.
A pickup unit 120 having a head (not shown) mounted thereon is arranged in the housing of a CD-ROM chamber. The pickup unit 120 is elevated by a level-positioning mechanism to be positioned at a predetermined level. The level-positioning mechanism, as shown in FIG. 10, has a cam plate having inclined guide groove portions 122 to which pins 121 projecting from both the side surfaces of the pickup unit 120 are guided, and a comb-like positioning member 124 in which positioning slits 123 are formed such that the number of slits 123 is equal to the number of disks.
When a desired disk is selected from the magazine which accommodates a plurality of disks therein, a motor (not shown) is driven to slide a cam plate to the right or left, and the pins 121 move along the guide groove portions 122, so that the pickup unit 120 is moved upward or downward. For example, if the lowermost disk is selected, as shown in FIG. 10, the motor is stopped at the level of the lowermost slit 123. Thereafter, a level determination pawl 125 which is drawn in the pickup unit 120 is inserted into the lowermost slit 123 by a level determination pawl projection mechanism (not shown). Thereafter, the positioning member 124 is slightly moved upward to put the lower surface of the level determination pawl 125 on the edge portion of the lower side of the lowermost slit 123. In this manner, the level of the pickup unit 120 on the lowermost stage is determined.
The disk on the lowermost stage is moved into the pickup unit by a tray loading mechanism, so that data is read/written between the disk and the head.
In the above prior art, after the pickup unit 120 is moved to a position near the position having a predetermined level by the cam plate having the inclined guide groove portions 122, the level determination pawl 125 is inserted into the comb-like positioning member 124, the level of the pickup unit 120 is determined on each stage selected in such a manner that the positioning member 124 is pushed up by the guide groove portions 122 of the cam plate. For this reason, a projection mechanism for the level determination pawl 125, a push-up mechanism for the comb-like positioning member 124, and the like are required to make the mechanisms complex, thereby increasing probability of an increase in cost and probability of fault. In addition, since the level determination pawl projection mechanism and the positioning member 124 in the pickup unit 120 are required, the device cannot be easily made compact. The level determination pawl projecting operation and the push-up operation of the positioning member 124 must be performed, and a period of time from the selecting operation to the loading operation is long.